Using a theoretical perspective of communities of practice, this case study examines a prospective chemistry teacher's inquiry-based teaching during his practicum. Conrad was a former student of an inquiry-oriented science course, "Inquiry Empowering Technologies" (IET). The research questions were (a) How did Conrad translate the IET inquiry practices during his practicum?; (b) How did the mentor teacher shape Conrad's participation?; (c) In what ways did Conrad negotiate new meanings of inquiry as a result of his practicum? Interview transcripts were the primary data source. Conrad carried many of the IET inquiry practices into his practicum. He equated inquiry with the use of evidence and had students create evidence-based explanations for how soap works. He chose not to incorporate the tentative nature of science. Although traditional in his own teaching, the mentor teacher supported Conrad by allowing him to teach through inquiry and by removing time constraints. As a result of his practicum, Conrad negotiated new meanings of inquiry teaching and developed an expanded view of technology. Conrad believed that high school students needed guidance when engaging in inquiry and that the tentative nature of science does not transfer to secondary chemistry. Implications for theory and practice are given.